Plant Diseases

Plant Diseases

Epidemics and Control

1st Edition - January 1, 1964

Write a review

  • Author: J. E. Van Der Plank
  • eBook ISBN: 9781483262130

Purchase options

Purchase options
DRM-free (PDF)
Sales tax will be calculated at check-out

Institutional Subscription

Free Global Shipping
No minimum order


Plant Diseases: Epidemics and Control provides a description of the methods of epidemiological analysis based on infection rates and the relation between the amount of inoculum and the amount of disease it produces. The book shows how to study the increase of pathogen populations and the epidemiological strategy to be adopted to control the epidemic of plant diseases. The text covers the calculation of the logarithmic increase of disease; use of epidemiology in the study of control; forms of sanitation; the use of resistant plant varieties; and the design of field experiments. Plant pathologists and breeders, agriculturists, horticulturists, research workers, teachers, and students will find the text invaluable.

Table of Contents

  • Contents


    Chapter 1 The Control of Plant Disease Studied as Part of Epidemiology

    1.1. The Population of Pathogens

    1.2. Epidemics and Biological Warfare

    1.3. The Language of Epidemiology. Some Expressions

    1.4. A Suggested Order of Reading the Chapters

    1.5. The Spread of Disease and Its Bearing on the Technique of Field Experiments

    Chapter 2 About Interest on Money. Logarithmic Increase


    2.1. Interest is Proportional to Initial Capital

    2.2. Interest per Cent and Interest per Unit

    2.3. Simple Interest

    2.4. Discontinuous Compound Interest

    2.5. Continuous Compound Interest

    2.6. Continuous Compound Interest Seen in Another Way

    2.7. Equivalent Rates of Continuous and Discontinuous Compound Interest

    2.8. Variable Rates of Continuous Compound Interest

    2.9. Consistent Units of Time

    2.10. Natural Logarithms

    2.11. Logarithmic Increase


    Chapter 3 The Logarithmic and the Apparent Infection Rates


    3.1. Statement of the General Problem of This Book

    3.2. The Intermittent Increase of Disease

    3.3. The Percentage and the Proportion of Disease

    3.4. Logarithmic Increase of Disease and Increase That Is Not Logarithmic

    3.5. The Meaning of Infection Rates

    3.6. The Words, "per Unit," Again


    Chapter 4 How to Plot the Progress of an Epidemic


    4.1. The Increase of Disease with Time

    4.2. Two Ways in Which Disease Can Increase with Time."Compound Interest Disease'* and "Simple Interest Disease"

    4.3. Increase of Disease by Multiplication. "Compound Interest Disease"

    4.4. The Increase of Disease without Multiplication. "Simple Interest Disease"

    4.5. The Correction Factor (l — x)

    4.6. The Reason for Using Log [1/(1 - x)] When There is No Multiplication



    Chapter 5 The Basic Infection Rate


    5.1. The Basic Infection Rate and the Latent Period

    5.2. The Incubation Period

    5.3. Some Biological Meanings

    5.4. The Early Stages of Artificially Induced Epidemics of Stem Rust of Wheat

    5.5. The Relation between r and R

    5.6. How R Changes as an Epidemic Progresses

    5.7. The Relation between r1 and R

    5.8. The Products pr1, pr, and pR

    5.9. The Limit to the Explosiveness of an Epidemic

    5.10. A Discontinuous Infection Model

    5.11. Period of Infection is Reduced to a Point Each Year and p is 1 Year


    Chapter 6 The Latent Period

    Summary 59

    6.1. Logarithmic Increase of Infection with p and R Constant

    6.2. The Variation of n with Time, with p and R Constant

    6.3. The Variation of r{ at an Average Value over an Interval of Time

    6.4. The Effect of a Prolonged Period of Inoculation on the Variation of r1

    6.5. The Effect of Variation of the Latent Period p on the Variation of r1

    6.6. A Wider Interpretation of r1

    6.7. The Error from Using a Constant Mean Value p in Eq. (5.7) Instead of a Constant Value p

    6.8. Increase of Infection beyond the Logarithmic Phase with p and R Constant

    6.9. The Estimation of n after the Logarithmic Stage of an Epidemic

    6.10. Three Arbitrary Stages in an Epidemic


    Chapter 7 Average Values of Infection Rates. Increase of Populations of Lesions and of Foci. Independent Action of Propagules


    7.1. The Relative Infection Rate as an Average

    7.2. The Logarithmic Infection Rate

    7.3. The Growth of an Individual Lesion in Relation to the Growth of a Population of Lesions

    7.4. The Growth of Foci

    7.5. The Spread of Pathogens in Relation to the Focal Pattern

    7.6. The Growth of an Individual Focus in Relation to the Growth of a Population of Foci

    7.7. The Mass Increase of Foci

    7.8. Massed Foci of Potato Blight. The Epidemic S

    7.9. The Independent Action of Propagules. The General Problem

    7.10. The Independent Action of Propagules. Puccinia graminis. Phytophthora infestons, and Some Other Pathogens

    Chapter 8 Corrected Infection Rates


    8.1. Correction of n and r for the Growth of the Host Plants

    8.2. Correction for Removals

    8.3. Relation between the Corrected Basic Infection Rate Re and r

    8.4. Balance in Epidemics

    8.5. Relation between Rc and r1

    8.6. A Threshold Theorem

    8.7. The Threshold Theorem and Control of Disease by Fungicides

    8.8. The Threshold in Epidemics of Two Systemic Diseases

    8.9. Looking Back

    Exercises and Examples

    Chapter 9 Stochastic Methods in Epidemiology


    9.1. Transforming Proportions of Disease

    9.2. Sampling Errors of Estimates of Infection Rates

    9.3. Deterministic and Probability Methods in Epidemiology

    9.4. Multiple Infections with Systemic Disease

    9.5. The Overlapping of Local Lesions

    9.6. The Influence of Numbers

    9.7. Comparisons with Medical Epidemiology

    Chapter 10 A Guide to the Chapters on Control of Disease

    10.1. The General Proposition

    10.2. Control Measures That Reduce xo: Sanitation, Vertical Resistance, and Chemical Eradication

    10.3. Control Measures That Reduce r: Horizontal Resistance and Protectant Fungicides

    Chapter 11 Sanitation with Special Reference to Potato Blight


    11.1. A Definition of Sanitation

    11.2. How the Infection Rate Affects the Benefit from Sanitation

    11.3. The Effect of the Sanitation Ratio

    11.4. The Effect of Sanitation on Disease after the Logarithmic Phase

    11.5. The Use of Eqs. (11.1) and (11.2) when Disease Is in Foci

    11.6. Phytophthora infestans from Potato Cull Piles

    11.7. Focal Outbreaks and General Epidemics of Potato Blight

    11.8. The Change from Focal Outbreaks to General Epidemics

    11.9. The Delay of the General Epidemic as a Result of Destroying Cull Piles

    11.10. Cull Piles and Blight Forecasts

    11.11. The Increase in Yield as a Result of Sanitation

    Chapter 12 Sanitation with Special Reference to Wheat Stem Rust


    12.1. Potato Blight and Wheat Stem Rust Contrasted and Compared

    12.2. Stem Rust and Barberry Eradication

    12.3. Focal Outbreaks and General Epidemics of Wheat Stem Rust

    12.4. Barberry Eradication and Wheat Stem Rust in Northwestern Europe

    12.5. The Relation between Sanitation and the Percentage of Stem Rust in Ripe Fields

    12.6. The Reduction by Sanitation of Loss in Yield

    12.7. The Relation between Loss of Yield and the Area under Stem Rust Progress Curve

    12.8. The Infection Rate in Relation to Benefits Gained from Sanitation

    12.9. Potato Blight and Wheat Stem Rust Compared Again

    Chapter 13 Sanitation and Two Systemic Diseases. Sanitation when Other Things Are Not Equal


    13.1. Common Bunt of Wheat and Fuearium Wilt of Tomatoes

    13.2. The Relation between the Number of Spores and Infection of Wheat by Bunt

    13.3. The Relation between the Number of Spores and Infection of Tomatoes with Fusarium Wilt

    13.4. The Effect of Sanitation on Disease of the "Simple Interest" Type

    13.5. The Benefit of Reducing Systemic Disease by Sanitation

    13.6. Dependability of Sanitation as a Method of Disease Control in Relation to rt

    13.7. Sanitation in Relation to the Absolute Amount of Initial Inoculum

    13.8. A Comparison between "Simple Interest" and "Compound Interest" Disease in Relation to Sanitation

    13.9. Two Kinds of Initial Inoculum


    Chapter 14 Vertical and Horizontal Resistance against Potato Blight


    14.1. The Relation between Races of Phytophthora infestons and Resistance Genes in the Potato

    14.2. The Mutability of Races of Phytophthora infestons

    14.3. Vertical and Horizontal Resistance

    14.4. The Unimportance of Vertical Resistance in Varieties without R Genes

    14.5. The Distribution of Races

    14.6. The Effect of Popularity on the Behavior of R-Types toward Blight

    14.7. The Place of Vertical and Horizontal Resistance in Epidemiology

    14.8. Analysis of Kirste's Findings: the Effect of Vertical Resistance

    14.9. Analysis of Kirste's Findings: the Effect of Horizontal Resistance

    14.10. Other Evidence for a Difference in Horizontal Resistance

    14.11. Some Published Assessments of Blight Resistance

    14.12. The Vertifolia Effect

    14.13. Blight on Solanum demissum

    14.14. Blight on Mixtures of Clones

    14.15. What Vertical Resistance Implies

    14.16. The Manifestations of Horizontal Resistance

    14.17. The Quantitative Determination of Horizontal Resistance when There Is Also Vertical Resistance

    14.18. The Deficiency of Horizontal Resistance in Commercial Varieties

    14.19. Breeding Potato Varieties for Resistance to Blight

    Chapter 15 A Note on the History of Stem Rust Epidemics in Spring Wheat in North America


    15.1. The Problem in the Spring Wheat Area of North America

    15.2. Some Early History

    15.3. Waldron's Evidence

    15.4. The Evidence of Stakman and Fletcher

    15.5. The First Class Epidemics

    15.6. Some Conclusions

    Chapter 16 Plant Disease in Biological Warfare


    16.1 Epidemics as Explosives

    16.2. Vertically Resistant Crops as a Target

    16.3. Wheat Stem Rust as an Example

    16.4. Stem Rust Races that Can Overcome Vertical Resistance

    16.5. Weather Adverse to Epidemics

    16.6. Horizontal Resistance for Defense

    16.7. Horizontal Resistance to Stem Rust

    16.8. Quantitative Interpretation of the Evidence

    16.9. The Transition


    Chapter 17 The Bases of Vertical Resistance


    17.1. Introduction

    17.2. The Different Response of Horizontal and Vertical Resistance to Diversity of Varieties

    17.3. The Dependence of Vertical Resistance on Varietal Diversity

    17.4. A Reason Why Vertical Resistance Is Commonly Chosen to Protect Varieties

    17.5. Diversity and Novelty

    17.6. The Fitness of Simple Races on Simple Varieties

    17.7. Evidence for Stabilizing Selection of Simple Races of Puccinia graminie tritici

    17.8. Vertical Resistance without Novelty

    17.9. Natural Stability in Vertical Resistance

    Chapter 18 General Resistance against Disease


    18.1. General Resistance

    18.2. Results of Troutman and Fulton and of Holmes

    18.3. The Commonness of Resistance

    18.4. The Need to Stress Affinities

    18.5. The Search for General Resistance

    Chapter 19 The Choice of Type of Resistance

    Summary 240

    19.1. The Aims of Plant Breeding

    19.2. The Difficulty about Generalizing

    19.3. The Usual Preference for Vertical Resistance

    19.4. The Case for Vertical Resistance

    19.5. The Possibility of Improving Vertical Resistance

    19.6. The Choice of Horizontal Resistance when There Has Been a Record of Varietal Change

    19.7. The Choice of Horizontal Resistance when rt Is High

    19.8. The Choice of Horizontal Resistance when There Is Danger of a Vertifolia Effect

    19.9. The Choice of Horizontal Resistance when There Is Danger of Biological Warfare

    19.10. The Choice of Horizontal Resistance when Fungicides Are Used

    Chapter 20 The Quantitative Effect of Horizontal Resistance


    20.1. The Components of Horizontal Resistance

    20.2. Changing the Basic Infection Rate

    20.3. A Return to Tables 16.3 and 16.4

    20.4. Relative Insensitivity of the Apparent Infection Rate to Change when the Basic Rate Is High

    20.5. The Effect of a Change of the Latent Period on the Apparent Infection Rate

    20.6. The Effect of Removals on the Apparent Infection Rate

    20.7. The Effect of Resistance

    20.8. The General Simplification

    Chapter 21 Control of Disease by Fungicides


    21.1. The Fungicide Square

    21.2. Laboratory and Glasshouse Experiments with Phytophthora infestans

    21.3. The Performance of Fungicides against Potato Blight in the Field

    21.4. Citrus Black Spot and Apple Scab

    21.5. The Calculated Effect of Horizontal Resistance or Adverse Climate on the Degree of Fungicidal Activity Needed

    21.6. Other Calculated Effects

    21.7. Variable Results with Fungicides and the Need for Recording

    21.8. The Timing of Application of Protectant Fungicides

    21.9. Eradicant Fungicides in Relation to the Infection Rate

    21.10. The Fungicide Frontier

    21.11. The Forgotten Factor

    Chapter 22 How Disease Spreads as It Increases


    22.1. Increase and Spread of Disease

    22.2. The Spread of Wheat Stem Rust

    22.3. The Spread of Potato Blight

    22.4. Wheat Stem Rust and Potato Blight Contrasted Again

    22.5. The Flattening of Gradients

    22.6. Increasing Disease and Increasing Scale of Distance of Spread

    22.7. The Behavior of Populations of Pathogens and of Individual Propagules; the Disease Triangle

    Chapter 23 The Cryptic Error in Field Experiments


    23.1. Errors of Representation in Results from Plots in a Field Experiment

    23.2. An Experiment with Tomato Fruit Diseases

    23.3. An Experiment with Leaf Rust of Wheat

    23.4. An Experiment with Stem Rust of Wheat and Rye

    23.5. The Deposition of Spores

    23.6. Some Calculations for Potato Blight

    23.7. Large's Observations on Potato Blight

    23.8. The Inadequacy of Guard Rows in Conventional Designs

    23.9. The Gradient Fallacy

    23.10. The Gradient Fallacy Illustrated

    23.11. The Cryptic Error

    23.12. Where the Onus of Proof Lies

    23.13. The Error when Unsprayed Plots Represent Unsprayed Fields

    23.14. The Loss of Air-borne Spores from Plots and Fields

    23.15. The Movement of Spores between Plots within an Experimental Area

    23.16. The Effect of the Size of Plot

    23.17. The Effect of Shape of Plot

    23.18. Interference between Plots

    23.19. Different Types of Experiment

    23.20. The Screening and Ranking of Fungicides in the Field

    23.21. Quantitative Comparison of Fungicide Treatments

    23.22. Experiments with Plots That Differ Greatly in Disease

    23.23. Variety Trial

    23.24. The Conservative Error Theory

    23.25. The Field Side of the Story



    Author Index

    Subject Index

Product details

  • No. of pages: 366
  • Language: English
  • Copyright: © Academic Press 1964
  • Published: January 1, 1964
  • Imprint: Academic Press
  • eBook ISBN: 9781483262130

About the Author

J. E. Van Der Plank

Ratings and Reviews

Write a review

There are currently no reviews for "Plant Diseases"